In joints of a concrete structure, the problem arises that a water passage is formed due to the secondary fluctuation of the joint or the coarseness or porosity of the placed concrete, which allows water to leak through the passage. To prevent the water leak, a rubber seal is conventionally provided at the joint. It has also been proposed to install a water-expansible seal in the joint to prevent the water leak.
However, in the conventional seals mentioned above, the problem arises that it is difficult to safely cope with internal cavities in the concrete structure at and near the joint so as to surely prevent the water leak.
The present invention was made in consideration of the problems mentioned above. Accordingly, it is an object of the invention to provide a seal for a joint which is composed of inexpensive structural materials in a simple manner so as to cope well with internal cavities at and near the joint and which performs a secondary sealing function as well as a primary sealing function.
It is another object of the present invention to provide a method of installing such a seal for a joint so as to completely produce not only a boundary sealing effect but also an additional capability to stop water.